Thomas a



(No Model.)

T. A. EDISON.

ELECTRICAL CONDUCTOR. v No. 304,087. I Y Patented Aug. 26, 1884.

WITNESSES INVENTOR UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEWV JERSEY.

ELECTRICAL CONDUCTOR.

fiPEC'Il-ICATION forming part of Letters Patent No. 304,087, datedAugust 26, 1884.

Application filed January 24, 1884. (No model.)

useful Improvement in Electrical Conductors,

(Case No. 613,) of which. the following-is a specification.

When the conducting-wires of an electriclighting system are placedoverhead upon poles, it is necessary to provide some means forcompletely isolating such wires, thereby preventing telegraph,telephone, or other wires from coming in contact with them, whereby thepowerful currents of the lighting-wire 1 would be transmitted to theinstruments in connection with the other wires, and also preventing thelighting-wires themselves from fallingfrom the poles, should they becomedetached from the insulators, and coming in contact with other wires, orwith any object contact with which would be undesirable. The first ofthese objects I accomplish by the use of guard-wires placed upon thepoles above the lighting-wires, and which prevent the other 2 5 Wiresfrom falling across or into contact with the lighting-wires. I extendthe cross-pieces to which the guard-wires are attached out far ther oneither side than those which carry the lighting-wires, and so bring theguard-wires 0 well outside of the vertical plane of the lighting-wires,so that it is impossible for any crossing wires coming from above toreach the latter. To prevent the lighting-wires themselves from leavingthe poles, and thus 5 from falling upon other wires, or upon any objectbelow them, I place supports upon the cross-pieces outside theinsulators. These supports are preferably pins inserted in the wood ofthe cross-piece, and of such height that 0 should the insulator bebroken, or the wire in any way become detached from it, the pin willkeep said wire from reaching the end of the cross-piece. The guard-wiresmay be of small size, and may be used, if desired, as testing-wires fordetermining the electrical condition of the different parts of thesystem.

Beyond the ends of the feeding-conductors, however, they are not soused.

My invention is illustrated in the accompanying drawing, whichrepresents the upper portion of one of the poles in a line of anelectric-lighting system.

A is the pole, and B B are cross-pieces which carry theelectric-lighting conductors O O, which are attached to suitableinsulators, a a. Above them is placed a larger cross-piece, D, whichcarries the guard-wires E E,.these being placed outside thelighting-wires for the purpose mentioned. Pins or supports 1) b areplaced outside the insulators on; the crosspieces B B, which prevent thewires from ever leaving the cross-pieces.

What I claim is- 1. The combination, with electrical conductors placedupon poles, of guard-wires placed above them, substantially as setforth.

2. The combination, with electrical conductors placed upon poles, ofguard-wires placed above them and outside their vertical plane,substantially as set forth.

3. The combination, with electrical conductors placed upon cross-piecesupon poles, of a longer cross-piece above them carrying guardwiresplaced outside their vertical plane, sub stantially as set forth.

This specification signed and witnessed this 12th day of January, 1884.

THOS. A. EDISON.

WVitnesses:

H. W. SEELY, EDWARD H. PYATT-

